Method of flanging can bodies having prestretched circumferential edges



Oct. 10, 1967 E. OBIDOWSKI 3,345,966 I METHOD OF FLANGING CAN BODIES HAVING PRES'IRETCHED CIRCUMFERENTIAL EDGES Original Filed May 27, 1963 3 Sheets-Sheet 1 INVENTOR EoMouD J. oanoowsm ATToRNEYs 452%, m, MB 8W Get. 10, 1967 E. J. OBIDOWSKI METHOD OF G CAN BODIES HAVING CUMFERENTIAL EDGES 5 Sheets-Sheet 2 PRESTRETC Original Filed May 27, 1963 INVENTOR EDMOND Joamowsn BY M, 6m

1967 E. J. OBIDOWSKI 3,345,966

METHOD OF FLANGING CAN BODIES HAVING PRESTRETCHED CIRCUMF'ERENTIAL EDGES Original Filed May 27, 1963 3 Sheets-Sheet 3 F: 3 9 .111. lol

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Ill]!!! I H 99 ins INVENTOR EDMOND J .Osuoowau MPAZAWS ATTORNEYS United States Patent ()fitice 3,345,966 Patented Oct. 10, 1967 3,345,966 METHOD OF FLANGING CAN BODIES HAVING PRESTRETCHED CIRCUMFERENTIAL EDGES Edmond .I. Ubidowski, Redessan, France, assignor to Continental Can Company, Inc., New York, N.Y., a corporation of New York Original application May 27, 1963, Ser. No. 283,332, now Patent No. 3,285,212, dated Nov. 15, 1966. Divided and this application Sept. 30, 1966, Ser. No. 583,395 5 Claims. (Cl. 113-120) This is a division of my pending application Ser. No. 283,332, filed May 27, 1963, now Patent No. 3,285,212, issued on Nov. 15, 1966.

This invention relates generally to the art of making metal can bodies and primarily seeks to provide a novel method of forming a flange on a can body such that the flange does not crack or shear along an edge of the flange.

In the manufacture of can bodies, it is common practice to form the can body either from a pre-cut blank or from a coil strip of thin highly tempered aluminum material or thin highly tempered tin-plated steel. It is also known in this art to tin-plate the steel prior to a final rolling operation to produce a very thin blank or strip. As a result of the rolling operation, the blank or strip becomes work hardened and less ductile. Thereafter, when a conventional flanging operation is performed to provide a can body with the usual flange for connecting a can end to the can body, small ruptures or shear lines are likely to occur in the flange.

The ruptures or shear lines occur incidental to the outward bending of the ends of the can body because the perimeter of the end of the can is considerably enlarged and the metal at the bend is stretched on one side and compressed on the other side thus producing shearing stresses which cannot be resisted by the work hardened blank or strip.

It is the purpose of the present invention to provide a novel method of forming flanged can bodies in such a manner as to solve the problem referred to above.

It is an object of this invention to provide a novel method of forming a flanged can body comprising the steps of providing a can body element, which element may be either a pre-cut blank or an elongated strip, prestretching at least one of opposite can .body end forming portions of the can body element, and performing a flanging operation on each of the prestretched end forming portions of the resultant can body.

Another object of the invention is to provide a novel method of forming a flanged can body in which the prestretching is accomplished by a coining operation to produce an undulating wave in that portion of the can body element from which the flange is made.

It is a further object of this invention to provide a novel method of forming a flanged can body comprising the steps of providing a can body element, coining and scoring the can body element along opposite can body end forming portions, and flauging the end portions of the can body.

In accordance with the above set forth object, it is another object of this invention to first perform the coining operation and then to perform the scoring operation.

In accordance with the above set forth object, it is a further object of this invention to provide a modified method of forming a flanged can body wherein the scor ing operation is performed before the coining operation.

In accordance with the above set forth object, it is another object of this invention to provide a further modified method of forming a flanged can body wherein the coining and scoring operations are performed simultaneously.

A still further object of this invention is to provide a modified method of forming flanged can bodies comprising the steps of providing an element for forming a plurality of can bodies with the element having opposed edges, forming a tubular member from the element, welding together the opposed edges of the tubular member, circumferentially coining and scoring the tubular member at intervals corresponding to the height of a can body, breaking the tubular member along the scoring to provide a plurality of can bodies having opposite end portions and fianging each can body along each end portion thereof.

With the above and other objects in view which will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claimed subject matter and the several views illustrated in the accompanying drawings.

In the drawings:

FIGURE 1 is a perspective view of a blank for forming a can body, the blank having a pair of edges which are to be joined together to form a tubular can body and a pair of end portions for forming opposite end portions of the can body.

FIGURE 2 is a schematic elevational view and shows the blank being disposed between an upper and a lower pair of cooperating coining rolls with part of the blank already having been coined.

FIGURE 3 is a plan view of FIGURE 2 and illustrates that the coining of the blank is limited to a small area along each of the opposite can body end forming portions of the blank.

FIGURE 4 is an enlarged cross-sectional fragmentary view taken on the line 44 of FIGURE 2 and shows the relative exemplary dimensions of the plate thickness and the amplitude of a wave or wrinkle produced by the coining operation.

FIGURE 5 is a greatly enlarged fragmentary view of the lower right-hand corner of the coined portion of the blank shown in FIGURE 3.

FIGURE 6 is an elevation view of a can body which is formed from the blank shown in FIGURE 1, after the blank has been coined as shown in FIGURE 3, and shows that the periphery of the end portion of the can has been enlarged with respect to the circumference of the can.

FIGURE 7 is a fragmentary cross-sectional view taken on the line 7-7 of FIGURE 2, and shows that the undulating curl formed by the coining operation curves alternately outwardly and inwardly of the wall of the can body.

FIGURE 8 is an enlarged fragmentary cross-sectional view taken on the line 8-8 of FIGURE 6 and shows the undulating inwardly and outwardly configuration of the coined portion at the top of the can body.

FIGURE 9 is a fragmentary view of a known type of machine for simultaneously flauging two end portions of a can body and graphically illustrates how the undulating curl formed by the coining operation is smoothened during the flanging operation.

FIGURE 10 is a fragmentary enlarged cross-sectional View taken on the line 10-10 of FIGURE 9 and shows a portion of an end portion of a can body cooperating with a flauging die and flauging ring.

FIGURE 11 is a diagrammatic side elevational view of a welding line for forming a continuous tube from a metal strip and which tube is separated into can bodies, the welding line being provided with a pair of cooperating scoring rolls for transversely scoring the strip at can body height intervals and a pair of cooperating coining rolls for transversely coining the scored strip in alignment with score lines formed thereon by the scoring rolls.

FIGURE 12 is a plan view of the welding line of FIG- URE 11 and shows the score line extending completely across the strip and the coining terminating at points slightly inwardly from the edges of the strip.

FIGURE 13 is a fragmentary cross-sectional view of the coining rolls in cooperative engagement to impress the undulating curl into the cam forming strip.

FIGURE 14 is an enlarged cross-sectional view on the line 14-14 of FIGURE 13 and shows the strip being coined directly over the previously formed score line.

FIGURE 15 is a fragmentary diagrammatic view of a tube for making can bodies with portions broken away, and shows apparatus for making a circumferential score line in the tube and apparatus for circumferentially coining the tube directly over a previously formed score line.

FIGURE 16 is a diagrammatic elevation view illustrating one form of the invention wherein the coining operation is performed prior to the scoring operation. 7 FIGURE 17 is fragmentary view partly in section, taken on line 17-17 of FIGURE 16, and shows the scoring rolls inscribing a score line on the previously formed coined area.

FIGURE 18 is a diagrammatic elevation view and il lustrates that form of the invention wherein the coining and scoring operations are performed simultaneously.

FIGURE 19 is an enlarged fragmentary portion of the coining-and-scoring rolls shown in FIGURE 18.

FIGURE 20 is a fragmentary cross-sectional view taken on line 2020 of FIGURE 19 and shows the strip engaging portion of one of the coining-and-scoring rolls.

Referring to the drawings in detail, and initially to FIGURES 1 to 10, there is shown a rectangular blank 10 for forming a can body, generally indicated by the numeral 11. The blank 11 includes a top edge 12, a bottom edge 13 parallel to the top edge 12, a first side edge 14, and a second side edge which is parallel to the first side edge 14. The edges 12 and 13 of the blank 10 are pre-cut to a measured length in accordance with the circumferential length of the finished can body 11, and the edges 14 and 15 are pre-cut to a measured length in accordance with the height of the can body 11.

The blank 10 is fed between an upper coining roll 16 and a lower coining roll 17 and is embossed with a plural ity of undulating protuberances along the top edge 12 and the bottom edge 13 to prestretch the balnk 10 along an area from which is formed a top flange 19 and a bottom flange 2.0 for the can body 11. Each of the coining rolls 16 and 17 is provide-d with a plurality of cogs 21 separated circumferentially by spaces 22. The cogs 21 on the coining roll 16 are designed for mating engagement with the spaces 22 of the coining roll 17 and the cogs 21 on the coining roll 17 are designed for mating engagement with the spaces 22 in the coining roll 16 to emboss the blank 10 with the protuberances 18. Each of the cogs 21 and spaces 22 diminish in cross-sectional area inwardly of the length of each roll 16 and 17 such that the amplitude of each of the protuberances 18 gradually diminishes into the planar body wall forming portion 23 of the can body 11.

The area of the blank 10 in which the protuberances 18 have been formed is prestretched such that the edges have been. elongated and stresses in this area of the blank 10 have been relieved. After the can body 11 has been formed by joining the first side edge 14 and the second side edge 15 by any known method to form a seam 24, the peripheral length of the edges 12 and 13 is greater than the normal circumference of the side wall 23. This prestretching of the flange forming portions of the blank 10 eliminates the ruptures and shear lines which normally are likely to be caused during the flanging operation to be hereinafter described.

Attention is directed to FIGURE 9 which shows can bodies 11 having prestretched top flange forming portions 19 and bottom flange forming portions disposed for engagement with first flanging dies on a left flanging turret 31 and second flanging dies 32 on a right flanging turret 33. Each flanging die 30 is provided with a flanging die slide 34 and a flanging ring 35. Corresponding parts are also provided for the flanging dies 32, all of which are known in the can making art.

Prior to the present invention it was the standard practice in the can making idustry to form the required flanges on the can body by stretching the metal at the ends thereof. When the flanging dies moved into the ends of the can body, shearing stresses were imposed thereon which caused rupturing or shear lines to occur at the edges as the metal of the end portions of the can body was stretched.

In accordance with the present invention, the bottom edge 13 and the top edge 12 of the can body 11 have been prestretched by the coining operation previously described such that when the dies 30 and 32 form the flanges 36 and 37, as shown in FIGURE 9, it is only necessary that the flange forming portions 19 and 20 be forced to conform to the shape of the dies 30 and 32. This allows the flanges 36 to 37 to form with very little stretching which is required only to eliminate or iron out the protuberances caused during the prestretching operation and thereby produce a can body 11 having the desired flanges which are required for the double seaming operation which is performed in connecting a can end to the can body.

A modified form of the invention is illustrated in FIG- URES 11 through 14 from which it will become apparent that the present invention is readily adaptable for use in making cans from an elongated strip of can body forming material. FIGURES 11 and 12 show a strip 40 being fed from a coil between cooperating scoring rolls 41 and 42 for forming score lines 43 completely across the strip 40. As the strip 40 continues to the right, as shown in FIG- URES 11 and 12, each score line 43 becomes disposed between an upper coining roll 44 and a lower coining roll 45 and is engaged by cogs 46 of the roll 44 and cogs 47 of the roll 45 such that the strip 40 is embossed with a series of protuberances 50 which extend transversely of the strip 40. As shown in FIGURES 12 and 13, the portion of the strip 40 which is embossed with the protuberances 40 ends slightly short of the marginal edges 51 and 52 so that the embossed protuberances 50 will not interfere with the forming of a welded seam 53, which joins the edges 51 and 52, at a welding station, generally indicated by the numeral 54, for forming the strip 40 into an elongated tubular member 55. Forge rolls 56 are provided at the welding station 54 to insure a proper seam 53.

A modified form of the invention is illustrated in FIG- URES 16 and 17 from which it will be apparent that the coining operation is performed prior to the scoring operation. A can body forming strip 60 is fed (from a source not shown) between an upper coining roll 61 and a lower coining roll 62. The coining rolls 61 and 62 are similar to the previously described coining rolls 44 and 45 and are provided with mating cogs 63 and 64 respectively. The embossed portion of the strip 60 is then fed between cooperating scoring rollers 65 and 66. As can be seen in FIGURES l5 and 17 the scoring roll 65 is provided with a scoring blade 67 for producing a score line 68 transversely of the strip 60 along the previously coined portion thereof.

The scoring blade 67, as is shown in FIGURE 17, is designed for mating engagement with the protuberances 69 formed in the strip 60 by the coining drums 61 and 62. The score line 68 extends completely across the strip 60 but the protuberances 69 of the embossed portion of the strip terminate short of the marginal edge of the strip 60 so as not to interfere with the welding operation which is to be performed in the manner described with reference to FIGURES 11 and 12.

In FIGURES 18 through 20, there is illustrated another form of the invention wherein the coining operation and scoring operation are performed simultaneously. A can body forming strip is fed from a source not shown between cooperating combined scoring and coining rolls 81 and 82 which are provided with mating cogs 83 and 84, respectively. In addition to the cogs 83, the roll 81 is also provided with a scoring blade 85. The scoring blade 85 corresponds to the general configuration of the cogs 83. As shown in FIGURE 20, the scoring blade 85 terminates at a marginal edge 86 of the roll 81 such that the strip 80 will be scored completely transversely of its length, while the roll 81 has cogs 83 which do not extend to the marginal edge 86 but terminate inwardly therefrom. Thus, the strip 80 is provided with a coined portion 87 and has a score line 88 therein.

After the strip 60 and the strip 80 have been coined and scored, as above described, the strips are shaped into tubular form, such as the tubular member 55 as shown in FIGURE 12, and a welding operation is performed to provide the resultant tubular members with a welded seam, such as the seam 53. The tubular members are then broken along their respective score lines so as to provide a plurality of can bodies. Each of the can bodies formed in this manner is provided with flange forming portions at the opposite edges thereof, which portions have been prestretched by the coining operation such that flanges formed by the apparatus shown in FIGURE 9, and described above, will not have ruptures or shear lines therein.

Another modified form of the invention is illustrated in FIGURE 15 from which it will be apparent that the scoring and coining operation may be performed after the tubular can body forming member has been welded. As shown, a tubular can body forming member 90 having a welded seam 91 is moving to the right as indicated by the arrow 92. A scoring device 93 is reciprocated along the path of travel of the tubular member 90, by means not shown, to produce longitudinally spaced circumferential score lines 94 in the tubular member 90. The scoring device 93 includes a scoring blade 95 which is mounted on an annular block 96 which is integral with an annular gear 97. The block 96 and the gear 97 have a passageway 98 centrally therethrough to permit passage of the tubular member 90. The scoring blade 95, block 96 and gear 97 are rotated about the longitudinal axis of the annular member 90 by a drive pinion 99 which is connected to a drive shaft 100 which is driven by a source of power, not shown.

A plurality of circumferential score lines 94 are formed at measured intervals along the length of the tubular member 90 such that the tubular member 90 may be subsequently broken along the score lines to provide a plurality of can bodies. Prior to the breaking operation, the tubular member 90 is coined circumferentially along the score lines 94 by a coining apparatus, generally indicated by the numeral 101. The coining apparatus 101 includes a coining roll 102 mounted on an annular block 103 which is integral with an annular gear 104. The coining apparatus 101 is reciprocated along the path of travel of the tubular member 90 by a form of reciprocating means not shown and the coining roll 102, block 103 and gear 104 are rotated by a pinion 105 which is connected to a shaft 106 which is driven by a source of power not shown.

The coining apparatus 101 is further provided with a back-up coining roll 108 which is eccentrically mounted on a shaft 109 which is positioned interiorly of the tubular member 90. The shaft 109 may be supported in cantilever fashion by supporting means, not shown, which are disposed above the strip which forms the tubular member 90 just prior to the welding station (such as the welding station 54 in FIGURE 12) which provides the seam 91 for the tubular member 90.

The scoring apparatus 93 and the coining apparatus 101 may be operationally mounted independent of each other or it may be preferable to interconnect these mechanisms by a connecting rod which is adjustable to space the scoring blade and the coining rolls 102 and 108 ,at various distances which correspond to the height of the desired can body. A retracting mechanism 110 is provided for retracting the scoring blade 95 out of engagement with the tubular member 90 prior to leftward movement of the scoring apparatus 93 upon completion of the cutting of score line 94. The coining apparatus 101 is also provided with a retracting mechanism 111 for retracting the coining roll 102 out of contact with the tubular member 90 prior to the leftward movement of the embossing apparatus 101 after the coining roll 102 has circumferentially embossed the tubular member 90.

The tubular member 90 is subsequently broken along the plurality of score lines 94 to provide a plurality of can bodies which have been prestretched at their edges along areas which are flange forming portions. The can bodies are subsequently operated upon by the mechanism shown in FIGURE 9 such that can end receiving flanges are formed on the can bodies without any ruptures or shear lines being formed therein.

While preferred forms and arrangements of parts have been shown in illustrating the invention, and preferred methods of prestretching the flange forming portions of the can bodies have been disclosed in detail herein, it is to be understood that variations in the forms and arrangement of parts and in the various method steps may be provided without departing from the scope of the invention as defined in the appended claimed subject matter.

What is claimed is:

1. The method of forming can bodies comprising the steps of providing a strip of material for forming can bodies, forming ,a tubular member from said strip of material, circumferentially coining and scoring the tubular member at intervals corresponding to the height of a finished can body, and breaking the tubular member along the scoring for providing a plurality of can bodies.

2. The method as defined in claim 1 wherein the tubular member is formed by joining opposite longitudinal edges of said strip of material.

3. The method as defined in claim 1 wherein the coining step is performed subsequent to the scoring step.

4. The method as defined in claim 1 including the additional step of flanging each can body along each end thereof.

5. The method of forming flanged can bodies comprising the steps of providing a strip of material having opposed edges, forming a tubular member from said strip of material, welding together the opposed edges of the strip of material, circumferentially coining and scoring the tubular member at intervals corresponding to the height of a finished can body, breaking the tubular member along the scoring for providing a plurality of can bodies having opposite ends, and flanging each can body along each end thereof.

References Cited UNITED STATES PATENTS 1,617,069 2/1927 McLaughlin 72177 2,444,465 7/ 1948 Peters 113-420 2,947,276 8/ 1960 Loughney 113-120 3,214,877 11/1965 Akin 72366 RICHARD J. HERBST, Primary Examiner. .R; G s ant x min 

1. THE METHOD OF FORMING CAN BODIES COMPRISING THE STEPS OF PROVIDING A STRIP OF MATERIAL FOR FORMING CAN BODIES, FORMING A TUBULAR MEMBER FROM SAID STRIP OF MATERIAL, CIRCUMFERENTIALLY COINING AND SCORING THE TUBULAR 